Inspection of the patents listed as cross references will introduce you to the Jet Ski type vehicles to which this invention relates. It is a small boat operated primarily in the standing position, narrow like a ski and powered by a jet of water from the rear. Many times control or balance is lost and the vehicle is overturned and otherwise very indiscriminately thrown upon the water. In the prior art a "U" shaped duct was inverted with the openings located near the center of mass, this provided ventilation and worked very well when the vehicle was upright. The "U" however became horizontal when the jet ski was held on it's side, this was not desireable and the situation was further worsen when Coast Guard regulations required addition of a forward facing air scoop into this system. Under certain condition the water would force into this air scoop, pass unrestricted directly into the engine compartment.
The present invention cures these faults with an improved method of circumferential ducting, locating the inlet and outlets at the top rear of the engine hood and providing water traps with small drains located in the ducts themselves. Thus if the craft is held on its side in the water the previously horizontal circumferential ducts now become vertical "U" shapes limiting the water access. Upon righting the water taken in, runs to the traps and is drained to the exterior of the boat.